Like if I had sex last week can I be pregnant

Yes, you could be pregnant. Where were you in your cycle?

Like Wondergirls says, yes you could be pregnant. Most sperm does its work in the first 45 minutes but can live inside a woman for a week.

like if i had sex last week can i be pregnant

It depends on whether you were near ovulation. If ovulation had already occurred prior to the sex or you were not close to it, the sperm would die off quickly. If you were getting close to ovulation, sperm could survive for several days. Most will die off after 2-3 days, but some can be quite hardy in the conditions leading up to ovulation.